Short answer: exterior shades stop the sun before it hits the glass. Interior shades manage light that has already entered and heated the room. For Texas afternoon sun, exterior wins on performance.
Below is how exterior shades and interior shades actually differ on cost, light control, lifespan and the rooms each belongs in, so you can decide per window rather than picking one for the whole house.
Exterior shades at a glance
- Mounted outside the glass, over patios, porches and windows
- Stop solar heat before it passes through the glass and into the room
- Keep a west facing patio usable at five in the afternoon in July
- Should be retracted in high wind, which is the main argument for motorizing them
Interior shades at a glance
- Mounted inside, with far more choice of style, colour and texture
- Manage glare, privacy and the look of the room all at once
- Cellular options insulate at the glass and cut heat transfer measurably
- Never exposed to weather, so they last on looks rather than on durability
The cost difference, honestly
Neither is a single price. Both are made to your openings, so the number depends on size, material, mount and whether you motorize. What is reliable is the ordering: within the same window, the option with more material and more hardware costs more.
The useful question is not which is cheaper overall, it is which one you want in the three or four rooms that matter most, and what goes in the rest of the house.
Lifespan and how they age
Anything on a west facing window in Texas ages faster than the same product on a north wall. Sun degrades fabric and warps light materials, and that is the single biggest factor in how long a treatment looks good.
- Rigid products hold their shape but show dust and fingerprints
- Fabric products are softer and warmer but fade if the weave is not rated for sun
- Anything on a hot wall should be specified for that wall, not chosen on looks
- Motors and hardware usually outlast the fabric they move
Why the order matters
Once sunlight is through the glass, the heat is in the room. An interior shade then blocks the light but the room has already gained the heat. That single fact is why exterior shading outperforms interior shading on a west wall, and it is the whole argument for patio shades in Texas.
Material decides more than format
Whichever of the two you choose, the material is what decides whether it still works in three years. On a west facing Texas window that is not a style question, it is the whole question.
Real wood
Lightest and takes stain beautifully, but it moves with humidity, so it belongs in dry living areas rather than bathrooms or over a sink.
Faux wood and composite
Handle moisture and hard sun without warping. Heavier, which matters across a wide span, but far more forgiving.
Fabric
Softer in a room, and the only option where openness factor lets you trade view against shade. Specify a weave rated for sun on a hot wall.
Daytime privacy is not night time privacy
This catches people out more than any other detail. A weave that gives complete privacy at midday can become see-through once it is dark outside and the lights are on inside.
- Decide per window whether it needs to work after dark
- Any inside mount leaks light at the edges, by design rather than by fault
- Layering a shade under a drape solves most cases one product cannot
- Blackout means overlap or side channels, not just opaque fabric
What we would ask at your consultation
- Which way does the window face, and when does it take direct sun
- Is this a room where you need real darkness, or just less glare
- Do you want to keep the view, or is privacy the priority
- Is the opening square and deep enough for an inside mount
- Is it a window you can comfortably reach every day
The verdict
Use exterior shading on the hardest sun and outdoor spaces, interior everywhere else. Most houses want both, and the west wall is where exterior shading earns its keep.
Or let us measure it
Every consultation includes measuring each opening on site. It is free, there is no obligation, and it removes the one risk that matters on a custom order: a treatment cut to the wrong number.
